- ID:
- ivo://CDS.VizieR/J/A+A/469/451
- Title:
- Radio continuum spectra of GPS galaxies
- Short Name:
- J/A+A/469/451
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent studies have shown that a remarkable share of quasars classified in the literature as gigahertz-peaked spectrum (GPS) sources and high frequency peakers (HFPs) are actually flaring flat-spectrum sources or blazars. Thus, at least among the quasar-type samples, genuine GPS sources and HFPs seem to be rare. We have studied variability and the shape of the radio continuum spectra of a sample of 96 galaxy-type GPS sources and HFPs in order to find out whether there is a similar contamination in the galaxy-type samples.
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- ID:
- ivo://CDS.VizieR/J/A+A/472/785
- Title:
- Radio continuum survey of M33
- Short Name:
- J/A+A/472/785
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the exponential scale length of total radio emission, the spectral index distribution, and the linear radio polarization in the Scd galaxy M33. Observations were carried out using the 3.6cm dual channel and the 6.2cm four-channel receivers of the 100-m Effelsberg telescope along with the L-band VLA D-array at 20cm. High spatial resolution and sensitivity in both total and linearly polarized radio continuum emission from M33 were achieved. We found considerable extended emission, not only from the main arms IS and IN, but also from the weaker arms. The large-scale magnetic field exhibits well-ordered spiral structure with almost the same orientation as that of the optical spiral arms; however, it does not show a clear structural correlation or anti-correlation with the optical arms. There is a north-south asymmetry in polarization that is frequency-dependent. We found that the ring mean spectral index versus radius increases faster beyond R=4kpc. At each wavelength, the exponential scale length is larger inside than outside R=4kpc. From the larger scale lengths at R<4kpc, we conclude that star-forming regions are mainly spread over the region R<4kpc without a dominant nuclear concentration. Furthermore, at R>4kpc, a spatial correlation between cosmic rays and star-forming regions may exist. From the behavior of the mean spectral indices obtained from different pairs of the radio continuum data at 3.6, 6.2, and 20cm, we confirm that a decrease in the thermal fraction causes an increase in the spectral index.
- ID:
- ivo://CDS.VizieR/J/A+AS/106/1
- Title:
- Radio data in Dumbbell galaxies
- Short Name:
- J/A+AS/106/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+A/416/35
- Title:
- Radio Emission from VLA FIRST Survey AGN
- Short Name:
- J/A+A/416/35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the most recent (April 2003) version of the VLA FIRST survey radio catalog (Cat. <VIII/71>), we have searched for radio emission from >2800 AGN taken from the most recent (2001) version of the Veron-Cetty and Veron AGN catalog (Cat. <VII/224>, superseded by 2003, Cat. <VII/235>). These AGN lie in the ~9033 square degrees of sky already covered by the VLA FIRST survey. Our work has resulted in positive detection of radio emission from 775 AGN of which 214 are new detections at radio wavelengths.
- ID:
- ivo://CDS.VizieR/J/AJ/126/2237
- Title:
- Radio-excess IR galaxies PMN/FSC sample selection
- Short Name:
- J/AJ/126/2237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A sample of 178 extragalactic objects is defined by correlating the 60{mu}m IRAS Faint Source Catalog (FSC, Cat. <II/156>) with the 5GHz Parkes-MIT-NRAO (PMN, Cat. <VIII/38>) catalog.
- ID:
- ivo://CDS.VizieR/J/A+A/552/A19
- Title:
- Radio-farIR correlation in NGC 6946
- Short Name:
- J/A+A/552/A19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive the distribution of the synchrotron spectral index across NGC 6946 and investigate the correlation between the radio continuum (synchrotron) and far-infrared (FIR) emission using the KINGFISH Herschel PACS and SPIRE data.
- ID:
- ivo://CDS.VizieR/J/ApJS/123/41
- Title:
- Radio galaxies in Las Campanas redshift survey
- Short Name:
- J/ApJS/123/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To increase the redshift range and look-back time over which the radio luminosity function can be measured directly, we identified 1157 galaxies in the Las Campanas Redshift Survey (LCRS, Cat. <VII/203>) having isophotal (red) magnitudes m_ISO_<=18.0 with radio sources brighter than 2.5mJy/beam in the 1.4GHz NRAO VLA Sky Survey (NVSS, 1998AJ....115.1693C). Since the NVSS has 45" FWHM angular resolution, these radio and optical limits include nearly all LCRS galaxies with 1.4GHz luminosities L>=10^22.4^W/Hz at z~0.05 to L>=10^23.6^W/Hz at z~0.2. The mean redshift <z>~0.14 of the radio-detected galaxies is higher than the mean redshift <z>~0.10 of the optical sample. This indicates that, statistically, the radio emission was detected from galaxies with the highest optical luminosities. Of the 1157 galaxies, 261 were also identified with far-infrared (FIR) sources in the IRAS Point Source Catalog and Faint Source Catalog. The principal radio energy sources in all identified galaxies were classified as either "starburst" or "AGN" on the basis of their FIR-radio flux ratios, FIR spectral indices, and radio-optical flux ratios. We show that the radio-optical flux ratio can be effectively used to classify the dominant energy source for the radio emission even if FIR fluxes and radio morphological data are not available.
- ID:
- ivo://CDS.VizieR/J/ApJS/134/355
- Title:
- Radio galaxies in 18 nearby Abell clusters
- Short Name:
- J/ApJS/134/355
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the use of the NRAO VLA Sky Survey (NVSS) to identify radio galaxies in 18 nearby Abell clusters. The listings extend from the cores of the clusters out to radii of 3Mpc (H_0_=75km/s/Mpc), which corresponds to 1.5 Abell radii and approximately 4 orders of magnitude in galaxy density. To create a truly useful catalog, we have collected optical spectra for nearly all of the galaxies lacking public velocity measurements. Consequently, we are able to discriminate between those radio galaxies seen in projection on the cluster and those that are in actuality cluster members. The resulting catalog consists of 329 cluster radio galaxies plus 138 galaxies deemed foreground or background objects, and new velocity measurements are reported for 273 of these radio galaxies. The motivation for the catalog is the study of galaxy evolution in the cluster environment. The radio luminosity function is a powerful tool in the identification of active galaxies, as it is dominated by star-forming galaxies at intermediate luminosities and active galactic nuclei (AGNs) at higher luminosities. The flux limit of the NVSS allows us to identify AGNs and star-forming galaxies down to star formation rates less than 1M_{sun}_/yr. This sensitivity, coupled with the all-sky nature of the NVSS, allows us to produce a catalog of considerable depth and breadth. In addition to these data, we report detected infrared fluxes and upper limits obtained from IRAS data. It is hoped that this database will prove useful in a number of potential studies of the effect of environment on galaxy evolution.
- ID:
- ivo://CDS.VizieR/J/MNRAS/333/100
- Title:
- Radio galaxies in the 2dFGRS
- Short Name:
- J/MNRAS/333/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use redshift determinations and spectral analysis of galaxies in the 2dF Galaxy Redshift Survey (<VII/226>) to study the properties of local radio sources with S>=1mJy. 557 objects (hereafter called the spectroscopic sample) drawn from the FIRST survey(<VIII/71>) , corresponding to 2.3 per cent of the total radio sample, are found in the 2dFGRS catalogue within the area 9h 48min<=RA<=14h 32min and -2.77{deg}<=DE<=2.25{deg} (2000), down to a magnitude limit b_J_=19.45. The excellent quality of 2dF spectra allows us to divide these sources into classes, according to their optical spectra.
- ID:
- ivo://CDS.VizieR/J/MNRAS/381/211
- Title:
- Radio galaxies in the 2SLAQ LRG Survey
- Short Name:
- J/MNRAS/381/211
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have combined optical data from the 2dF-SDSS (Sloan Digital Sky Survey) LRG (Luminous Red Galaxy) and QSO (quasi-stellar object) (2SLAQ) redshift survey with radio measurements from the 1.4GHz VLA (Very Large Array) FIRST (Faint Images of the Radio Sky at Twenty-cm) and NVSS (NRAO VLA Sky Survey) surveys to identify a volume-limited sample of 391 radio galaxies at redshift 0.4<z<0.7. By determining an accurate radio luminosity function for luminous early-type galaxies in this redshift range, we can investigate the cosmic evolution of the radio-galaxy population over a wide range in radio luminosity.
